The Dissoci'it/n I'mrcrs of Free tunl nf Combined Water. 



TABLE 104. 

 Molar for KNO.i; 0.698 molar for Ca(NO 3 ) 2 . 



127 



DISCUSSION OF RESULTS. 



The conductivity values to be found in the second and fourth 

 columns of tables 100 to 104 are not the sums of the specific conduc- 

 tivities of the two salts present in each case, but are less than this 

 sum because of the common ion effect. Furthermore, since the two 

 solutions in any given case contain the same number of anions, the 

 added salt not being considered, the driving back of the dissociation 

 of the added salt by these anions, other things being equal, would 

 be the same. An inspection of the tables will show that for every 

 pair of solutions studied this suppression is more pronounced in the 

 hydrated solutions. Or, stating it in another way, the increase in 

 conductivity caused by the addition of the same amount of added salt 

 is always greater in the non-hydra ted solutions. This means that the 

 added salts dissociate more in the last-named solutions than in the 

 comparable isohydric solutions of hydrated salts. 



A closer inspection of the tables reveals the fact that the driving 

 back of the ionization of the hydrated salts added is much greater than 

 the driving back of comparable quantities of non-hydrated salts in 

 both isohydric solutions of every pair studied. A comparison of tables 

 102 and 103 will show that for any one added salt the difference 

 in the increases of conductivity in table 102 is approximately double 

 the corresponding difference in table 103. Finally, a few salts were 

 added which do not have ions in common, and these behaved in 

 somewhat the same manner as the other added salts, though the results 

 are somewhat irregular. How can all these facts be explained? 



